It is common practice in modern day web fed printing to have the web pass through a plurality of printing stands and to perform a printing function at each stand. This is true, for example, in an operation where multiple colors are being printed on the traveling web. In situations such as the multiple-color printing mentioned, it is obviously necessary that each successive area where printing is to be effected be precisely located so that it falls within the predesignated area on the web. This positioning requirement obviously means that the plates on the plate rolls in the successive printing stands must be in precise, predetermined locations with respect to both lateral and circumferential positions. When proper alignment is attained, the printing plates are referred to as being in register.
The problem of placing printing plates in register is one that has been recognized in the graphic arts industry for many years. As a problem of long standing, it should be apparent that it has been the subject of a variety of solutions, which solutions have attained various degrees of effectiveness. Generally speaking, prior art mechanisms for seeking registration have involved two separate adjustment mechanisms, the circumferential adjusting device being on the drive side of the press and the side-lay or lateral adjusting device being on the operating side of the press. Adjustment was usually effected by means of hand-wheels and screw threads and/or gearing. Devices for adjusting circumferential or lateral register, or both, which are representative of those in the prior art can be seen in U.S. Pat. Nos. 2,566,399; 3,717,092; 4,137,845; 4,207,815 and 4,336,755.